Before I order some (I want spares on hand for an oddball thread fastener) can someone confirm that these are the M9 nuts/washers/gaskets?
M9x1.25 nut
https://www.suzukipartshouse.com/oemparts/a/suz/5e20716b87a866135c5d0bc8/cyli...23 NUT 09159-09003 $5.09 quantity 3
24 NUT 09159-09004 $2.95 quantity 1
25 GASKET (10.2X20X2.3) 09168-10031 $2.95 quantity 3
26 GASKET (10.2X20X2.3) 09168-10031 $2.95 quantity 1
In the early 1970s Suzuki often had fastener sizes in the part number, so I'm thinking the "-09" starting the second part of the nut part indicates M9. But since I will need to order the parts and pay shipping as well as a high price, I'd like to make sure I've got the correct parts.
I found reference to an M9 nut that is used on a variety of Italian scooters,
Vespa Input/Aux Shaft Nut Piaggio M9x1.25 (V6K-4940001)
but that is a plain nut and at least some of the Suzuki parts appear to be acorn nuts.
McMaster has some 12 point M9 flange nuts at $5.32 each
https://www.mcmaster.com/products/nuts/thread-pitch~1-25-mm/thread-size~m9/but that doesn't seem to be a more economical choice.
There are plenty of bikes that manage to get by with either M8 or M10 threads on the cylinder studs, so I'm at a loss for why Suzuki had to go with an oddball size. OEM prices seem to range up to $7-8/nut.
Are there any other non-standard fasteners on the engine that I need to be aware of?